A drive circuit of a conventional liquid crystal display device is generally in the form of an externally attached integrated circuit module, such as the commonly used tape automated bonding (TAB) package structure. However, with the development of low temperature poly silicon (LTPS) semiconductor thin-film transistors that have ultrahigh carrier mobility, the integrated circuit technology based on panel peripherals gradually becomes a focus of researches. A typical application in this respect is the gate driver on array (GOA) technology.
A GOA drive circuit uses a liquid crystal display array process to manufacture a gate scanning drive signal circuit on an array substrate, so as to drive scanning on pixel units gate by gate. The GOA drive circuit can reduce soldering operations for connecting an external integrated circuit and improve integration, and can also improve productivity and reduce production costs, and therefore is a preferred choice for small- and medium-sized liquid crystal display products (such as mobile phones and PDAs). In addition, with increasing acceleration of a smart-up process of mobile phones, corresponding technical support is required for the touch control technology applied to small- and medium-sized liquid crystal display devices. Therefore, more requirements are imposed on drive circuits.
The GOA drive circuit in the prior art has the following problems. On the one hand, parameters of a transistor are greatly distributed, and performance of the transistor may be affected after long-time working, further causing changes of the parameters. As a result, voltages on some critical circuit nodes in the drive circuit may change. This may cause a failure of a designed time sequence and function in a severe case, and further cause a failure of the entire GOA drive circuit. On the other hand, in a process of manufacturing the GOA drive circuit, faults, such as short circuits or open circuits, easily occur due to reasons such as a large quantity of circuit poles or a large quantity of transistors. In addition, repair difficulty is high. As a result, once such a fault occurs, a liquid crystal panel becomes a defective product, severely affecting a yield rate of liquid crystal panels.